If we attack first, and Russia retaliates by sinking Navy Ships full of sailors.
Most war game scenarios with Russian show us going to thermonuclear war within hours of this starting.
Not the ones I’ve seen. In general, two nuclear powers, each of which has a second strike capability, will not start a nuclear war because the other side will obviously retaliate with nukes. In other words, the initiator of a nuclear war is literally committing suicide, because the second strike will target command and control, i.e. the people who gave the order. That is why even at the height of the Cold War, when Americans and Russians killed hundreds of their opposite numbers, with Russians tallying up bigger numbers because of their manning of SAM sites and US air superiority, nothing even close to nuclear war materialized. National leaders all have a finely-honed sense of self-preservation.
“Not the ones I’ve seen.”
As soon as one side perceives they are losing, they will go to tactical nukes first...then everything comes undone.
That’s every scenario I saw during the height of the Cold War.